In the process of adding people to your community an invitation is sent to all households with email addresses. This allows the members of your community to update their information in the system. The updated information is then available to you as the administrator. A specific default message is emailed depending on whether or not the household is already in the system for another group.
Just Between Friends will now offer you, as the administrator, the opportunity to customize your message for your group and override the default text. The instructions will guide you on the simple process.

There are two types of messages which go out when entering people with email addresses; those who have never been added to the system and those who are linked to another group in the system (already in the system with the email address you are using for their household).
The system will know which households are new, you may not. This should not be a concern. You may wish to just make the messages the same or use the default language as a guide.